Global Volcanism Program | Image GVP-04513
Steam plumes rise above the Danau Asam fumaroles on the west side of lake Asam within the 8 x 16 km Suoh depression in SE Sumatra. The depression appears to be primarily of tectonic origin, but contains historically active maars and silicic domes along its margins. Hot springs occur along faults and the Pematang Bata fumarole field are within the depression. Prior to a large explosive eruption in 1933 the floor of the Suoh depression was a broad marsh 13 km long in a NNW-SSE direction.